Question

尝试在sqlite数据库表中查询所有行时，我收到以下异常：

08-24 20:36:48.134: E/AndroidRuntime(351): java.lang.RuntimeException: 
Unable to start activity ComponentInfo{se.p950tes.workouttracker/se.p950tes.workouttracker.SavedActivity}:
android.database.sqlite.SQLiteException: no such column: col_distance: , 
while compiling: SELECT _id, col_date, col_time, col_distance, col_route FROM workout

我还没有更新数据库，这是我第一次在这个设备上安装应用程序，并且它也在模拟器上进行了测试，结果相同。即便如此，我还是尝试了几次版本号，没有任何变化。

这是我的代码。 getAll方法抛出异常。

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DatabaseHandler
{
    public static final String DATABASE_NAME = "workout_tracker";

    private static final String KEY_ID       = "_id";
    private static final String KEY_DATE     = "col_date";
    private static final String KEY_TIME     = "col_time";
    private static final String KEY_DISTANCE = "col_distance";
    private static final String KEY_ROUTE    = "col_route";

    private static final String TABLE = "workout";
    private static final String[] ALL_FIELDS = {KEY_ID, KEY_DATE, KEY_TIME, KEY_DISTANCE, KEY_ROUTE};

    private static final int DATABASE_VERSION = 3;

    private final Context context;
    private DatabaseHelper helper;
    private SQLiteDatabase db;

    public DatabaseHandler(Context context)
    {
        this.context = context;
        this.helper = new DatabaseHelper(context);
    }

    public void connect()
    {
        db = helper.getWritableDatabase();
    }
    public void disconnect()
    {
        db.close();
    }

    public Cursor getAll()
    {
        return db.query(TABLE, ALL_FIELDS, null, null, null, null, null);
    }

    private static class DatabaseHelper extends SQLiteOpenHelper
    {
        private static final String CREATE = "CREATE TABLE " + TABLE + "("
                                                + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
                                                + KEY_DATE + " INTEGER NOT NULL, "
                                                + KEY_TIME + " INTEGER NOT NULL, "
                                                + KEY_DISTANCE + "INTEGER NOT NULL, "
                                                + KEY_ROUTE + " BLOB NOT NULL"
                                                + ");";
        DatabaseHelper(Context context)
        {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }
        @Override
        public void onCreate(SQLiteDatabase db)
        {
            try
            {
                db.execSQL(CREATE);
            }
            catch(SQLException e)
            {
                e.printStackTrace();
            }
        }
        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
        {
            Log.w("DBHandler", "Upgrading database from version "+oldVersion+" to "+newVersion+", which will destroy all old data");
            db.execSQL("DROP TABLE IF EXISTS "+TABLE);
            onCreate(db);
        }
    }
}

我意识到这个“我为什么会得到这个SQLiteException”的问题被问了很多，但到目前为止，我见过的大多数问题都没有用引号括起字符串等等。如果结果是重复，我会提前道歉。

Answer 1

您错过了"INTEGER NOT NULL, "中的前导空格。

SQLiteException：查询数据库时没有这样的列

1 个答案: